96 lines
2.6 KiB
Markdown
96 lines
2.6 KiB
Markdown
# API styleguide
|
||
|
||
This styleguide recommends best practices for API development.
|
||
|
||
## Instance variables
|
||
|
||
Please do not use instance variables, there is no need for them (we don't need
|
||
to access them as we do in Rails views), local variables are fine.
|
||
|
||
## Entities
|
||
|
||
Always use an [Entity] to present the endpoint's payload.
|
||
|
||
## Methods and parameters description
|
||
|
||
Every method must be described using the [Grape DSL](https://github.com/ruby-grape/grape#describing-methods)
|
||
(see <https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/api/environments.rb>
|
||
for a good example):
|
||
|
||
- `desc` for the method summary. You should pass it a block for additional
|
||
details such as:
|
||
- The GitLab version when the endpoint was added
|
||
- If the endpoint is deprecated, and if so, when will it be removed
|
||
|
||
- `params` for the method params. This acts as description,
|
||
[validation, and coercion of the parameters]
|
||
|
||
A good example is as follows:
|
||
|
||
```ruby
|
||
desc 'Get all broadcast messages' do
|
||
detail 'This feature was introduced in GitLab 8.12.'
|
||
success Entities::BroadcastMessage
|
||
end
|
||
params do
|
||
optional :page, type: Integer, desc: 'Current page number'
|
||
optional :per_page, type: Integer, desc: 'Number of messages per page'
|
||
end
|
||
get do
|
||
messages = BroadcastMessage.all
|
||
|
||
present paginate(messages), with: Entities::BroadcastMessage
|
||
end
|
||
```
|
||
|
||
## Declared params
|
||
|
||
> Grape allows you to access only the parameters that have been declared by your
|
||
`params` block. It filters out the params that have been passed, but are not
|
||
allowed.
|
||
|
||
– <https://github.com/ruby-grape/grape#declared>
|
||
|
||
### Exclude params from parent namespaces!
|
||
|
||
> By default `declared(params) `includes parameters that were defined in all
|
||
parent namespaces.
|
||
|
||
– <https://github.com/ruby-grape/grape#include-parent-namespaces>
|
||
|
||
In most cases you will want to exclude params from the parent namespaces:
|
||
|
||
```ruby
|
||
declared(params, include_parent_namespaces: false)
|
||
```
|
||
|
||
### When to use `declared(params)`?
|
||
|
||
You should always use `declared(params)` when you pass the params hash as
|
||
arguments to a method call.
|
||
|
||
For instance:
|
||
|
||
```ruby
|
||
# bad
|
||
User.create(params) # imagine the user submitted `admin=1`... :)
|
||
|
||
# good
|
||
User.create(declared(params, include_parent_namespaces: false).to_h)
|
||
```
|
||
|
||
>**Note:**
|
||
`declared(params)` return a `Hashie::Mash` object, on which you will have to
|
||
call `.to_h`.
|
||
|
||
But we can use `params[key]` directly when we access single elements.
|
||
|
||
For instance:
|
||
|
||
```ruby
|
||
# good
|
||
Model.create(foo: params[:foo])
|
||
```
|
||
|
||
[Entity]: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/api/entities.rb
|
||
[validation, and coercion of the parameters]: https://github.com/ruby-grape/grape#parameter-validation-and-coercion
|